Sword and Circle by GJ Kelly (The Longsword Chronicles)

With the Kings' Council at Ferdan reeling from the sight of Morloch and the shock of betrayal by wizards of the D'ith, the King of Raheen rides in haste once again to his devastated homeland. There, he hopes, the wizard Allazar will discover the reason for Morloch's dread on learning the true identity of the Longsword DarkSlayer, Gawain, King of Ashes. And there, he hopes, that reason, if revealed, can be used against Morloch and the dark armies of the north gathering in the wastelands beyond the farak gorin.

But some things are, perhaps, best left shrouded in the mists of myth. The nature of the conflict between the kindred races of Man and Morloch is about to change forever...